From industrial facilities such as thermal power generation equipment, a large amount of carbon dioxide (hereinafter, referred to as CO2) is discharged due to combustion of fossil fuel such as coal and fuel oil. Emission limitation of CO2 has been considered from the viewpoint of prevention of global warming, and as one measure, there has been the CO2 separation and recovery technology.
For industrial facilities such as a thermal power plant that uses a large amount of fossil fuel, a method of eliminating and recovering CO2 in combustion exhaust gas by contacting combustion exhaust gas of a boiler with amine based CO2 absorbing liquid, for example, and a method of storing the recovered CO2 without discharging it to the ambient air have been known.
Moreover, as a step of eliminating and recovering CO2 from combustion exhaust gas using the CO2 absorbing liquid as described above, a step of contacting the combustion exhaust gas with the CO2 absorbing liquid in an absorbing tower and a step of heating the absorbing liquid that absorbed CO2 in a regeneration tower to release CO2 as well as regenerate the absorbing liquid for circulation to the absorbing tower to be reused have been adopted.
Patent Literature 1 discloses that, in a regeneration tower, MEA (monoethanolamine) solution is regenerated due to heating by a regenerative heater (reboiler) and cooled by a heat exchanger to be returned to a CO2 elimination tower.